Video player does not work in Safari (JSF)

1. install nuxeo
2. install DAM addon
3. install JSF UI addon
4. login with Chrome
5. create a workspace
6. create a Video document
7. attache a video
8. wait for the processing to complete (check ffmpeg is not running any longer)
9. refresh the document
10. try to read the video through the player
11. observe it works
12. try the preview
13. try to read the video through the player
14. observe it works
15. now try both reads using Safari it fails (see attached screenshots)

Expected behavior: the preview should work in Safari as it does in Chrome.
Note: this does not happen in 8.10 and works fine.
Note 2: this also happens in Web UI (see ELEMENTS-895)